This invention relates to means for determining the angular displacement of the vertical axis of a bottle in reference to its base.
Typically, in most beverage processing plants or the like, bottles are filled by means of automatic high speed machines. During the filling process the individual bottles are arrested in a vertical position against a positioning stop. A filler tube is then brought down into the bottle opening and a metered amount of fluid dispensed therein. It has been found that the opening of a defectively formed bottle may be offset in reference to the center of its base whereby the bottle "leans" to one side of its vertical axis. The amount of lean can be relatively high whereby a filler tube, rather than being passed into the bottle opening, will be brought down against the neck of the bottle. In the case of a glass bottle, the bottle will be shattered. A deformable plastic bottle, on the other hand, will generally become forced or wedged within the filler tube. In any event, the production line must be shut down while the equipment is cleaned, inspected and/or repaired. This, of course, is a time consuming operation which usually proves to be costly.
Heretofore, a number of devices have been devised for inspecting bottles for excessive lean in an attempt to avoid breakage problems during filling. These inspection devices, for the most part, have not proven to be wholly satisfactory in actual use. In operation, the devices are difficult to set up, subject to misalignment and susceptible to human error. Moreover, most of the inspection devices known in the prior art utilize the outside surface of the bottle's neck as the critical reference point in the inspection process. Because the neck of most bottles is relatively thick, it is highly likely that the outside surface of the neck can be within prescribed limits while the opening contained therein is out of tolerance.